Many housings, such as telecommunications housings, contain and environmentally protect electronic circuit cards, such as line cards, management cards, splitter cards, repeater cards, or the like. These housings often contain one or more cases to confine circuit cards to different locations within the housings. Typically, these cases are thermally conducting and are thermally coupled to the circuit cards and to the housing. The housing acts as a heat sink, and heat is transferred from the circuit cards to the case, from the case to the housing, and from the housing to the environment surrounding the housing. However, many housings, such as 819-type repeater housings, are fabricated from materials, such as plastics, that are poor heat conductors and thus are not effective as heat sinks. In some applications, heat sinks are secured to outer surfaces of the housing and extend though apertures in the housing to make thermal contact with the cases. However, a pressure differential is frequently imposed between the interior and exterior of the housing, and it is difficult to seal these apertures against the pressure differential.
For the reasons stated above, and for other reasons stated below that will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for alternatives for sealing housings against pressure differentials.